So farewell then, deutschmarks, francs and lire. This is the last day that most of the traditional currencies of Europe will buy a schnapps, a vin rouge or an espresso. From midnight tonight, when the euro becomes legal tender in 12 European Union countries, these will be ex-currencies, of decorative value only. National currencies are dead; long live the euro.

It is an odd day of history – the moment at which so many famous currencies vanish for ever. And yet – theoretically at least – the British remain unaffected. Britain, proud of its traditions and (less explicably) its currency, has stayed clear of what opponents describe as this "euro-barmy" scheme. As Rudyard Kipling almost said: we will keep our currency, while all about us are losing theirs.

In Britain, we will continue to use pounds sterling (at least until a probable referendum in 2003). But, we, too, are affected. For a start, there are all the coins and banknotes which languish in British homes from one year to the next – a reminder of places we have visited, and a promise of places to which we hope one day to return. Three hundred drachmas here, 3,000 lire there – it is the smell of holiday sunshine.

As of tonight, those coins and banknotes are strictly for nostalgia only; if you proffer your drachmas or lire in cafes in Rhodes or Rome this summer, you will be greeted with disdain. From mid-February at the latest, Britons' most popular holiday destinations form part of the euro-only world.

That is one reason why we will be affected by the euro change. From tomorrow, most Europeans will only ever have to change currencies when they travel long haul. A Berliner will be able to buy a newspaper in Barcelona; the same money will be valid in Sicily and in Strasbourg. For the Brits, however, that's a different story. Each time we go abroad, we will have to change our money into their money. Each time we change money it will involve a loss. That is one reason why many of us have until now allowed assorted foreign currencies to pile up at home.

A few days ago, I bought £40 worth of French francs at Waterloo station, for a Eurostar trip to Paris. Except, of course, that it wasn't really £40 that I bought. Once the minimum commission has been deducted, the amount received is less than the number you first thought of (on this occasion, £3.95 less). And then it is the same story when you get home. Exchange counters, as any holidaymaker or businessman knows, are a pricey business.

Until now, most Britons have been overwhelmingly suspicious of the new currency. It is not hard to imagine a time, however, when the main feeling will be one of envy, for the Europeans who are paid in the same currency which they spend, at home and across most of the continent.

At least in one respect, Britons will benefit from the introduction of the euro. When they come home, they will be able to spend their euros with ease. It will no longer be necessary to spend (yet more) money to change their European holiday currency back into pounds sterling. From Marks and Spencer to the Body Shop, from Waterstone's to NCP car parks, the euro will be an acceptable currency. (Even Dixons, whose boss likes to be seen as a chief europhobe, will accept the foreign interloper in its tills.) All of which means that the mood is less cheerful among those who believe that the euro in Britain will spell the beginning of the end for all that we hold most dear, from British bangers to the smell of freshly mown grass.

Still, the Eurosceptics are used to changing their arguments. The goalposts have repeatedly moved. When planning for a European single currency started in earnest a decade ago, we were assured that talk of the euro (as it was not yet called) was mere Franco-German fantasy. Then, as it became clear that the foreigners were serious about their plans, the tone changed: it was insisted that the economic conditions could never be met; the essential austerity measures meant that there would be popular revolt in the countries seeking to sign up for the new currency.

Then, when the popular revolts did not materialise (and the single currency did), the focus shifted. We heard endless stories about the failures of the new virtual currency (failures which were real enough, because of a stumbling start); we were assured that no sane Briton would ever vote for such nonsense. How could British voters ever choose to give up the Queen's head on their banknotes? What an absurd idea!

And then came the line that William Hague peddled in this year's general election. He argued that a Labour victory would mean the euro would become inevitable. He was almost certainly right. Embarrassingly, however, he omitted the clear implication of his statement: that a majority of the population will, in just a few years' time, choose to vote in favour of such a change. He might as well have said aloud: "Now, most Britons are wary of a single currency. Within a couple of years, however, millions of you will come to think my views on the euro as plain barmy."

For years, Downing Street has seemed too cowardly to tackle the euro issue head-on, fearing the Eurosceptic backlash. Now, however, British pragmatism may prove useful. From tomorrow, when the euro banknotes and coins can be crumpled and jingled in our pockets, that alien currency will seem less of a threat.

Now is the perfect moment for the Government to launch a campaign in favour, as it is apparently planning to do. If we see that Italy is no less Italian, France no less French and Greece no less Greek, we may even find ourselves won over. In short: hoard those 20-pence coins and £5 notes for nostalgic reasons only. Soon, those British coins and banknotes may be as historic as 500-lire coins or 50-franc notes.